Firefox 159 fixes 167 security flaws, including 13 sandbox escapes

The Dell Laptop Buying Guide 2026: Which XPS or Alienware Laptop Should You Buy? The Dell Laptop Buying Guide UK: Which Dell Laptop Should You Buy? When you purchase through links in our articles, we may earn a small commission. Firefox 159 also puts a password tool in the sidebar by default and adds Smart Window, which watches sites for changes. Firefox 159 has been released for Windows, macOS, Linux, and Android.